Strengthened and vibration-damping shaft for sports equipment

ABSTRACT

A strengthening and vibration-damping shaft for sports equipment has a tube, a central body accommodated inside the tube, and multiple damping holes defined in the central body partly or completely along the length of of the central body. The central body provides a supporting efficiency to the shaft to prevent the shaft curving or deforming when the shaft is being swung. The damping holes mitigate and decrease vibration transmission to eliminate most vibrating energy. Therefore, the shaft has less vibration to keep the shaft steady for accurate hitting without deformation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a shaft for sports equipment, and more particularly to a shaft that has strengthening and vibration-damping efficiency.

2. Description of Related Art

Many items of sports equipment have a shaft, especially badminton rackets and golf clubs, wherein the shaft is long and thin. Conventional II shafts in such equipment have a simple tubular structure without any strengthening element. Therefore, the shaft is easily deformed and curved by a reacting force when being violently swung to hit a ball. The deformation of the shaft causes an inaccurate trajectory of the ball so that a user can not precisely determine the destination of the ball. Additionally, vibration that occurs during impact of the ball and shaft causes injury to the user's hands.

The present invention has arisen to mitigate or obviate the disadvantages of the conventional shaft for sports equipment.

SUMMARY OF THE INVENTION

The main objective of the present invention is to provide a strengthening shaft that has a central body accommodated inside the shaft to enhance supporting efficiency.

Another objective of the present invention is to provide a vibration-damping shaft that has multiple holes defined in the central body to provide a shock minimizing efficiency.

Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an intersected perspective view of a golf club with a strengthening and vibration-damping shaft in accordance with the present invention;

FIG. 2 is a partially enlarged perspective view of the strengthening and vibration-damping shaft in FIG. 1, wherein a flat central body extends inside the shaft;

FIG. 3 is a partially cross-sectional side plane view of the strengthening and vibration-damping shaft, wherein multiple damping holes are formed throughout the shaft all;

FIG. 4 is a partially cross-sectional side plane view of the strengthening and vibration-damping shaft, wherein multiple damping holes are formed in only a portion of the shaft;

FIG. 5 is a partially cross-sectional perspective view of another embodiment of the strengthening and vibration-damping shaft for sports equipment in accordance with the present invention, wherein a cruciform central body is accommodated inside the shaft; and

FIG. 6 is a partially cross-sectional perspective view of still another embodiment of the strengthening and vibration-damping shaft for sports equipment in accordance with the present invention, wherein the shaft is oval in cross-section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A strengthening and vibration-damping shaft for sports equipment in accordance with the present invention comprises a tube, a central body accommodated inside the tube, and multiple damping holes defined either entirely or partly along the length of the central body. The central body provides a supporting efficiency to the shaft to prevent the shaft curving or deforming when the shaft is being swung. The damping holes mitigate vibration transmission and so eliminate most vibrating energy. Therefore, the shaft has less vibration whereby the comfort and strength enable the user to keep the shaft steady for accurate hitting of balls etc.

With reference to FIGS. 1 and 2, a first preferred embodiment of the strengthening and vibration-damping shaft (30) used in a golf club comprises a tube (10) round in cross-section, a flat central body (15) extending inside the round tube (10), and multiple cutouts (152) defined in the flat central body (15).

The round tube (10) has an inner channel (102) with an inner periphery. The flat central body (15) is longitudinally accommodated inside the inner channel (102) and has two sides respectively abutting to the inner periphery of the round tube (10). The multiple cutouts (152) are longitudinally defined in the flat central body (15) at intervals and respectively at sides of the flat central body (15). Each of the multiple cutouts (152) is a segment with an arcuate edge and a flat edge, wherein the flat edge is adjacent to the inner periphery of the round tube (10). Thereby, the cutout (152) forms a damping hole (20) inside the shaft (30) to mitigate and decrease vibration transmission along the shaft.

With further reference to FIGS. 3 and 4, arrangements of the damping holes (20) can be varied. In FIG. 3, the damping holes (20) are longitudinally defined in sides of the flat central body (15) at intervals along the entire length of the flat central body (15) to eliminate the vibration gradually. In FIG. 4, the damping holes (20) are selectively defined in partial sections at sides of the flat central body (15) at intervals but not over the entire length of the flat central body (15). With reference to FIG. 5, a second preferred embodiment of the strengthening and vibration-damping shaft has the same structure with the first embodiment except that the central body ( 16) is cruciform in cross section. The cruciform central body (16) correspondingly has four sides respectively connected to the inner periphery of the round tube (10). Multiple damping holes (20) are defined in each side of the cruciform central body (16).

With reference to FIG. 6, a third embodiment of the strengthening and vibration-damping shaft for sports equipment has an oval cross-section tube (101).

Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

1. A strengthening and vibration-damping shaft for sports equipment comprising: a tube having an inner channel with an inner periphery; a central body longitudinally accommodated inside the inner channel and having at least two sides respectively abutting to the inner periphery of the tube; and multiple damping holes longitudinally defined in the central body at intervals.
 2. The strengthening and vibration-damping shaft as claimed in claim 1, wherein the multiple damping holes are respectively defined at sides of the central body.
 3. The strengthening and vibration-damping shaft as claimed in claim 2, wherein each of the multiple damping holes is a segment with an arcuate edge and a flat edge; and the flat edge of the damping hole is adjacent to the inner periphery of the tube.
 4. The strengthening and vibration-damping shaft as claimed in claim 3, wherein the multiple damping holes are defined along an entire length of the central body.
 5. The strengthening and vibration-damping shaft as claimed in claim 3, wherein the multiple damping holes are defined along part of a length of the central body.
 6. The strengthening and vibration-damping shaft as claimed in claim 1, wherein the central body is cruciform in cross-section.
 7. The strengthening and vibration-damping shaft as claimed in claim 1, wherein the central body is straight in cross-section.
 8. The strengthening and vibration-damping shaft as claimed in claim 1, wherein the tube is round in cross-section.
 9. The strengthening and vibration-damping shaft as claimed in claim 1, wherein the tube is oval in cross-section. 